[libsmi] smistrip - incorrectly matches MACROs within a comment

I modified smistrip to match the MACRO statement with more a explicit regexp so that it doesn't match a commented out MACRO statement.

The line I changed the line from:

/ *MACRO *::=/ {

to:

/^[ \t]*[A-Za-z0-9-]* *MACRO *::=/ {

Can this be added to CVS?

Steve